Demoralization and intimidation, basically. They did it once, and if they get away with it they can do it again, so everybody who sits on the presidential chair has to be extra careful while the military has to deal with such a high level of failure to their morale.

If there are no repercussions, this also opens up possibilities for more straightforward assassinations. Assassinating Maduro first would be too much, but now all lesser officials are on the table.

Before there's ever any land invasion there'll be a massive bombing campaign like in Libya and Yugoslavia to completely destroy the country's organisation and force capitulation. This is just another step in that escalation.